I think the easiest way to create a build up, or climax, is to breakdown your song from the start and build it up to the hook.
In other words, lets say your song consists of drums, bass, keys, horns, and strings.
Try starting each verse with just the drums and bass for 4 bars. Then bring in the keys for the next 4 bars. Then bring in the horn section and let that play all together for the next 8 bars until you get to the hook. At that point, the strings will come in and play the hook for 8 bars. Then back to the drums/bass again to start the next verse. And keep cycling like that throughout the song, or if you add a bridge somewhere too.
This way it keeps building up to the sweet spot/hook and prevents monotony.
The key to doing it like that though is to make sure each track can stand on its own and sound good. Sometimes you have two tracks like bass and keys that sound good together, but if you were just going to play the bassline by itself with the drums it could sound weak.
When arranging this way, I like to build the sound in the same steps as I plan to arrange it. So I would start doing the drums and bass first and make sure they are really tight together by themselves. Then add the keys and make sure that sounds good together without needing the horns or strings on top to make it sound good. And so forth building up the track to the strings.
And then periodically you can add fill-ins where necessary to spice it up a bit if you want.
A great example of what I'm talking about is Timbalands "Its Your Night". Great beat that starts out simple, and builds to an amazing climax of synths at the end.